She can be found at the 188 Trading Post. She can be recruited in Jacobstown after gaining the quest Guess Who I Saw Today. Can be recruited after completing One for My Baby and choosing particular dialogue. He can be found at night in the dinosaur at Novac. All permanent companions have a unique quest line that can be followed in order to 'upgrade' them, usually giving them new armor or new perks.
It is possible to have up to two legitimately acquired companions in the party (one humanoid and one non-humanoid). From left to right: Rex, Cassidy, Raul (Vaquero outfit), Lily, Boone (assault armor), ED-E, Veronica, and Arcade. All eight permanent companions in Fallout: New Vegas.